Here is the abstract you requested from the IMAPS_2013 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Ultrasonically Enabled Low Temperature Electroless Plating for Advanced Electronic Manufacture|
|Keywords: electroless, ultrasound, deposit|
|Electroless plating is an important process for the metallization of non-conductive substrates and is therefore widely utilized throughout the electronics and packaging industry. Electronic manufacture now requires processes and materials that can meet the demands for miniaturisation and reliability since holes and via diameters in both PCBs and microelectronics are being reduced whilst aspect ratios are getting higher. It is critical for the future development of electronics that manufacturing processes become adapted to meet these requirements. In terms of electroless plating, miniaturisation means that ensuring full coverage in vias and holes is extremely challenging whilst the electroless deposit structure is important to ensure high reliability, high conductivity etc. In addition the plating process must be able to meet the need for high production volumes (i.e. high deposition rates) whilst enabling more sustainable, low energy manufacturing. Performing electroless plating in an ultrasonic field has great potential to enhance the deposit properties and meet these advanced manufacturing requirements. Ultrasound, via the phenomenon of acoustic cavitation, will induce microjetting in an solution and this can affect electrochemical processes through thinning of the Nernst diffusion layer (Drake, 1980, Trans IMF, 58(2), 67-71) and improved mass transport (Compton et al, 1996, J.Appl. Electrochem., 26, 775-784) as well as affecting the crystal structure of the deposit (Dobrev et al, 1999, Appl.Phys. A69, 233-237). The effects of ultrasound on electroless plating has been studied since the 1960’s (Kuzub and Mukhlya,1963, Zhurnal Prikladnoi Khimii (Sankt-Peterburg, Russian Federation), 36, 2762-27640) and benefits such as increased plating rate (e.g. Touyeras et al, 2001, Ultrason.Sonochem.,8, 285-290), changes to the deposit composition (Mallory, 1978,Trans. IMF, 56, 81-86) and enhanced corrosion resistance (Tomlinson and Sexton, 1990, J. Mat. Sci. Lett., 9, 420) have been reported. This paper will discuss the results from the IeMRC funded ULTIEMet (Ultrasonically enabled Low Temperature Immersion and Electroless Metallisation) research project which has utilized a methodology incorporating a mixture of electrochemical and laboratory plating tests. It has been found that by optimising how ultrasound is introduced to the electroless process benefits such as reduced temperature plating, enhanced coverage and a finer grain structure deposit can be realised.|
|Dr Andrew J Cobley, Director
The Functional Material Applied Research Group at Coventry University
Coventry, West Midlands